Water jacket for machine guns



June 19, 3934. s. s. GREEN WATER JACKET FOR MACHINE GUNS Filed Feb. 29. 1932 wMMuv /w I H I HMWMH HUM UNI Hwwwww H HHWI MMMH. UH M H H H M M H A.

INVENTOR. Samuel L". Green M/ F W ATTORNEY Patented June 19, 1934 UNETED STATES FATE @FFifiE 5 Claims.

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a cooling system for machine guns.

In machine guns where the barrel is surrounded by a cooling fluid such as water it is the usual practice to provide a.valved steam escape tube having an outlet at the front end of the water jacket. This means of cooling the barrel has been found to be inadequate when the gun is to be fired for uninterrupted'periods at an increased rate of speed as is necessary in employing it against aerial targets. In order to obtain effective cooling under the most severe conditions of operation it is essential to circulate the cooling fluid.

The general purpose of the present invention is to provide a circulating system in the cooling jacket that may also serve as a steam escape system when the circulation of the cooling fluid is not employed. It is also proposed to provide a simplified construction that will facilitate manufacture and assembly and enable the outlet or return line of the cooling fluid to be conveniently positioned in proximity to the axis of elevation of the gun.

With the foregoing and other objects in view, the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

A practical embodiment of the invention is illustrated in the accompanying drawing, wherein:

Fig; 1 is a longitudinal sectional View, partly in side elevation, of the improved cooling system.

Fig. 2 is a sectional view on the line 2-2 of Fig. 1.

Fig. 3 is a view on the line 3-3 of Fig. 1.

Figs. 4 and 5 are views in side elevation of a modified. valve and tube.

Referring to the drawing there is shown the front portion of a machine gun including a jacket A and a gun barrel B.

The jacket consists of a cylinder 5 and a threadedly connected rear end cap 6 and front end cap '7. The end caps contain bearings for supporting the barrel but the particular character of the mounting is not pertinent to the present invention.

An aperture 8 in the rear upper portion of the cylinder 5 provides for the admission of a cooling fluid, conveniently water. The fitting to be placed in the aperture will depend on the employment or non-employment of a pump for circulating the fluid.

The circulating system provided within the jacket resembles the steam escape system usually employed in machine guns without circulation of the cooling fluid. Referring to Fig. 1 the circulating system comprises a pair of tubes 99 connected by a rigid bar 10. The front tube 9 is supported in a hollow plug 11 threaded into I the front cap 7 while the rear tube 9 is supported in one end of a double-elbowed pipe 12. The tubes 9 are each provided with an inlet port 13. A sleeve 14 mounted on the tubes 9 with a free sliding fit is slidable relative thereto and will cover only one of the inlet ports 13 depending upon the condition of elevation or depression of the gun. The sleeve is limited in its sliding movement by engagement with the plug 11 and pipe 12. In any position of adjustment the sleeve constitutes a fluid passage between the tubes 9.

As shown in Fig. 2 the outer end 15 of the elbow pipe 12 is inserted through an aperture 16 in the cylinder and secured in place as by welding. This end is internally threaded as at 17 to receive a fluid line (not shown).

At the forward end of the front tube 9 there is an outlet port 18 which is in communication through a similar port 19 in the plug 11 with a passage 20 formed in the front cap. At the outer end of the passage threads 21 are provided for receiving a plug or a fluid line as the method of operation requires.

In the modification shown in Figs. 4 and 5 a single tube 22 replaces the tubes 9 While two sleeves 23-23 interconnected by a bar 24 replace the single sleeve 14. This departure from the usual arrangement of two full-length tubes is made to reduce weight and friction to a minimum.

When the cooling system is to be employed without circulation of the fluid, the sleeve 14 and tubes 9 function in the accepted manner to enable the steam to be conducted out of the jacket. The outlet for the steam may be at either the front or rear. The rear outlet will usually be preferred because of the opportunity afforded for condensation and because its proximity to the axis of elevation of the gun will consequently reduce the length of the external fluid line with t a minimum of interference during elevation of the gun.

When the cooling fluid is to be circulated, any steam that is formed will be carried along with the fluid. In order to insure against the building up of pressure and the formation of air pockets, the inlet ports 13 and the front and rear outlets are of sufficient capacity to freely pass the fluid under all conditions of operation.

I claim:

1. A jacket for gun barrels including a cylinder, a front end and a rear end cap on the cylin-- der, a hollow plug in the front cap, a double-elbowed pipe secured on the rear portion of the cylinder and having one end projecting therethrough, a fluid conduit including a valved inlet adjacent each end mounted in the hollow plug and in the elbowed pipe, an outlet port in the conduit adjacent the front inlet, an outlet passage in the front cap in communication with the outlet port in the conduit, andmeans for admitting a fluid into the jacket.

2. A jacket for gun barrels including a cylinder, a front and rear end cap on the cylinder, a hollow plug in the front cap, a double-elbowed pipe secured on the rear portion of the cylinder and having one end projecting therethrough, a fluid conduit including a valved inlet adjacent each end mounted in the hollow plug and in the elbowed pipe, and means for admitting a fluid into the jacket.

3. A jacket for gun barrels including a cylinder, a front and rear end cap on the cylinder, a double-elbowed pipe secured on the rear portion of the cylinder and having one end projecting therethrough, and a fluid conduit mounted in the front cap and in the elbowed pipe.

4. A jacket for gun barrels including a cylinder, 2. front and a rear end cap on the cylinder, a pipe securedon the rear portion of the cylinder and having one end projecting therethrough, and a fluid conduit mounted in the frontwcap and in the pipe.

5. In combination with a jacket for a gun barrel, a fluid conduit Within the jacket and an outlet fitting in the rear portion of the jacket supporting the conduit and having fluid communication therewith.

SAMUEL G. GREEN. 

